A number of portable electronic communication devices and systems exist for enabling a user for their mobile operation in multiple applications. Usually one or more antennas are required to support such operation. A conformal, and preferably hidden, antenna system configuration is a key element to facilitate the portability and to increase the aesthetic appeal of these devices. However, during device operation, most antennas are subject to signal obstruction and frequency detuning or offset due to the presence of external agents that may electromagnetically couple to the antenna. Normally the antenna system is configured to operate while physically mounted on the communication device. However, portable devices are subject to unpredictable operational conditions and the effects of both electrically conductive and dielectric surrounding materials may significantly impair the antenna performance.
This situation becomes more critical for antenna applications used in handheld electronic devices, such as phones, tablets, and computers, in which the user inherently may affect the antenna performance and overall functionality of the specific device. In particular the body parts of a user, including hands, fingers, and head, may drastically degrade the antenna operation. Moreover, the antenna performance may be affected even in operational conditions where the device is put on a desk, placed in a pocket, or hung on clothing or where conductive materials or dielectric materials are located within a radius of two wavelengths at the lowest frequency of operation in the medium where the antenna is operating. Accordingly, the design, aesthetics, and operational characteristics of a handheld electronic communications device may be severely restricted.
Recently, the demand for handheld devices has increasingly grown for multiple applications in the wireless communication industry. In order to provide antenna solutions for these devices, previous efforts have been made to implement wideband antenna elements, as described in U.S. Pat. No. 8,749,438 to Jenwatanawet et al. and U.S. Pat. No. 8,766,856 to Hsieh, et al. However, these efforts typically include using an antenna operating at frequency ranges larger than required to reduce or prevent antenna detuning out of the intended frequency band of operation. A major limitation of these approaches occurs where the antenna is exposed to transmit or receive spurious signals that may increase the noise level of and/or interfere with internal and external electronic systems.
More specifically, other attempts made to implement antenna solutions to overcome frequency detuning while complying with signal integrity standards set up by industry have not been successful. For example, although enclosing the antenna in a separate module may make the antenna less susceptible to being detuned by an external agent, this approach requires a larger size and more expensive solution which is in conflict with long-existing electronic industry trends. Similarly, the approaches attempting to implement multiple antenna elements operating at different frequency bands increase the size requirements of the device and demand for more circuitry complexity.
Additional efforts that have been made to develop an antenna system and method to design a desensitized antenna element are described in U.S. Pat. App. Publication No. 2015/0061961 by Bayram, et al. However, these efforts have faced certain challenges and limitations. A limitation of this approach is that the desensitized antenna element requires at least one electrical circuit component to be added to the antenna. Another limitation of this approach is that both the antenna and additional circuitry is intended to be incorporated as part of the overall device design. While this approach may mitigate antenna frequency detuning, it may not be used in devices in which the desensitized antenna element was not part of the original design. As a result, this approach may not only require increased cost and circuit complexity of a new device in which this solution is implemented, but also may not be suitable for other devices.
Accordingly, the use of a wireless device in an antenna-detuning environment or certain constrained operational conditions may be subject to unacceptable frequency detuning and subpar system performance. This have led to the implementation of antenna solutions that are more complex, costly, aesthetically unappealing, or more importantly, highly inefficient by using wideband antennas, adaptively tuned antenna elements, multiple antenna elements, or automatic mechanisms to increase the power transmitted by the device.
An approach to tackle the disadvantages of the prior art is to implement an antenna desensitization system that provides a configuration and positioning of an antenna desensitizer element, with respect to an antenna of an electronic device, to overcome a potential frequency detuning during operation of such antenna. The antenna desensitizer element may be integrated as part of the original design of the electronic device design or added on aftermarket. This approach improves the overall performance of the antenna system by reducing the antenna frequency detuning effects caused by an external agent, such as a user or the unexpected presence of a surrounding object, during operation of such device.
Currently, there is no well-established method of deterministically creating an antenna desensitization system unless an electrical circuit component is added and the system is a primary part of the original antenna design. Thus, there remains a need in the art for antenna systems and methods to desensitize antennas that are capable of a robust operation at the frequencies of intended operation, while avoiding the problems of prior art systems and methods.